Load gripping device for hoist



Oct. 8, 1963 D. .1. wYRouGH LOAD GRIPPING DEVICE FOR HOIST United States Patent 3,106,421 LOAD GRIPPING DEVlCE FR HOIST David J. Wyrough, Maple Heights, Ohio, assigner to National Castings Company, a corporation of Ohio Fiied May 22, 1961, Ser. No. 111,843 6 Claims. (Cl. 294-83) `typical container of this system comprises four top-corner fixtures, each of which vprovides an yupwardly opening pocket horizontally bridged by a short rod-like element.

The customary way of lifting such containers is by the g use of a four-leg swing consisting essentially of four equal-length cables, each attached at its end to a ring common to the three other cables, and supporting a hook at its lower end. In coupling a crane carrying the fourleg swing, it is necessary VforV 1a workmancto manually connect each hook with one of the corner lixtureelements. Apparently, no hoisting equipment capable of automatically coupling with the Conex type of container in a satisfactory manner has heretofore been available.

It is a primary object of this invention to provide devices adapted to be -attached to a hoisting implement which automatically connects the implement to a load-article of the type `providing vertically-accessible, horizontallyextending elements of small vertical cross section, cgi, rod-like struts, rungs, rings, loops, etc.

Other objects in accordance with the foregoing object are to provide a device that (1) :has adequate gathering or aligning capability `in approaching rinten-ded loads;

. (2) is mechanically simple and operative; (3) is remotely e controllable by mechanical, electrical or hydraulic control systems; and (4) affords theY handling of containers i of the type hereinbefore mentioned solely by crane manipulation.

These and other objects are achieved in a lifting device ordinarily attached to a crane, or hoisting implement suspended therefrom, `for, the purpose of connecting a load with the crane. The lifting device, which may 'be used singly or in `a plurality on the hoisting equipment, comprises basically, a pair of relatively movable jaws having separable portions providing V:gripping surfaces facing into a central article-gripping region adjacent the load receiving end of the device.

Essential lfeatures contributing to automatic operation of the `device are:

(l) The jaws havea pair of opposed wedge-engaging surfaces of which each faces a direction generally opposite` to that in which the concave surface of the parent jaw faces, and a wedge element for chock insertable from a position permitting separation off the jaw portions to a position between the wedge-engaging surfaces holding the jaw portions nearer each other; and j `(2) The jaws have a pair of cam sur-faces, one on each j jaw, engagealble in concertby a load-article entering the article-gripping region to cam the jaws apart. The cam surface of each jaw is inclined relative to the length of the jaw toward the article-receiving en-d of the device and is contiguous with the end of the article-gripping surf-ace of that jaw further away'from such article-receiving end. The cam surface is of sufficient length to extend through a medial separation plane for both jaws at all positions of such jaws'. The two cam surfaces of t-he device hence form a notch contour facing into the article-receiving regiontoward the aforementioned end of the device.

In a preferred embodiment, the jaws of the device are pivotally connected, one of the jaws being of double-wall construction adapted to receive a `single wall of the other jaw therebetween. The `double-walled jaw is extended to form a U-shaped housing deiining a pocket in conjunction with an outer edge surface of the other jaw adapted to receive a lock or wedge member.

In the drawing in respect to which this invention is described:

FIG. l is an elevation partially in section showing the device of the invention with its jaws in closed load-lifting position.

FIG. 2 is an elevation partially in section of the device of FIG. l viewed in this same direction with its jaws open to receive a load-article.

FIG. 3 is an elevation illustrating the device at `an intermediate stage of jaw closing.

FIG. 4 is a plan view of the -device with its parts -arranged as shown in FIG. 1.

FlG. 5 is a vertically shortened elevati-on partially in section showing the device of the Iforegoing figures in plurality and in position within a spreader.

EIGL 6 isa perspective yfragmentary view of a container and the spreader of FlG. 5 in separated relationship.

FIGS.V 1, 2, and 3 show the device 5 in various stages of operation beginning with the completely closed position of FIG. 1, wherein a wedge or lock piece 6 is seated between a housing surface 7 and an abutment area 8 of a single-walled jaw 1@ disposed between two spaced, generally parallel walls 11 and 12 of the double-Walled jaw M. 'lhe jaw-s are connected in pivotal relation by a pin 13 having a longitudinal axis 3.

As shown in FIGS. l to 4, the jaw 14 comprises a housing portion 15 which projects beyond the portion of its walls 'overlapping the single-wall jaw 10 at closed position to define a pocket 18 `for receiving the-wedge 6 in its various positions. The housing 15 also provides a support in conjunction with a pinV 19 for pivotallysupporting a bell-crank 21. To accommodate the cam arm 22 `ot the bell-crank, the wedge 6 is constructed lwith an opening 2.4 closed across the top by a wall 2S.

1n placing the device 5 in condition for separation of portions 23 and 29 of the jaws, the lever, by its cam arm 22, engages the underside of the wail 25 and may be rotated to a position of the lock and arm as shown in FIG. 2. When the wedge 6 is so raised, a spring 31 seated at one end on a bridge or cross piece 32 of the jaw ll4, and at its other end in a cylindrical recess or bore 33, pivots the jaws 1G and 14 relatively to each other to separate portions 28 and 29 thereof. The retraction of the wedge 6 is accomplished preferably with the device in a slack condition relative to an eiement 3S of a load article.

Any lifting exerted by the device 5 on the element 3S makes it difficult if not impossible to retract the wedge 6.

Gn the other hand, resting of the device 5 on the element 35 by engagement therewith of cam surfaces 37 and 38 tends to draw the jaws more tightly together and to release the wedge 6 from surfaces 7 and 8. Wedge retraction is thus facilitated.

The wedge 6 is movable relative to the jaws in an ambit extending toward and'away from the load-receiving end of the device. extending generally lengthwise of the jaws and toward and away from the pivotal axis 3 of the jaws.

The wedge surface of the jaw 10 traversed by the wedge 6 comprises the aforementioned area 8 engaged at articleretaining or closed position of the jaws, and a recessed area 4l terminating at its end further away from the article-receiving end of the device in a shoulder area 42. Areas S and 41 are connected by a transition area 43.

This ambit is aligned in a direction The area 4l has a length approximately as long as the opposing surface 4d of the wedge 6 in order that the body portion of the wedge may seat thereagainst in the articiereleasing or open position of the device depicted in FIG. 2.

The length of the wedge openings 24 allows return of the bell-crank 21 of each device to the position shown in dot-dash outline (same as that in FIG. l) with the wedge 6 retracted as shown in FIG. 2. Return of the bell-crank to the position shown in dot-dash is an essential condition enabling automatic coupling of the device with the loadarticle, such as a rung 35. That is to say, the wedge d must be free to drop into position, as shown in FIG. 1. However, prior to such coupling the wedge 6 is held in the recess formed by areas 41, ft2, and 43.

FIG. 3 illustrates the device 5 at an intermediate stage of coupling with the element 35.- As shown, the element has engaged the cam surfaces 37 and 38 and, through sliding contact therewith, has brought the jaw portions 2S and 29 nearer together than shown in FIG. 2. Simultaneously, the wedge 6 has moved toward the area S. Corner 5S of the wedge surface 44 rests against the transition surface 43. The inclination of surface 43 relative to the path of the wedge 6 is outside the angle of repose, i.e., the maximum angle of a surface that will frictionally engage the surface 44 to prevent movement toward the retracted position. At the stage shown in FIG. 3, the wedge 6 tends to be cammed backwardly toward a position against surface 4rif the Velement Sifor any reason is disengaged from cam surfaces 37 and 38. However',V

as coupling action is continued by maintenance of pressure of the element against the cam surfaces, the corner 5S of the wedge moves past the hump or juncture 56 of the areas 8 and 43 to dispose surface 44 in overlapping relation with the area 8. Thus, the Wedge 6 enters into irreversible wedging relation with area 8 of the jaw. With continued cam action between the element 35 and the surfaces 37 and 3S, the device then progresses irreversibly through a series of adjustments in which the jaw portions 28 and 29 are forced toward each other to reach the ultimate closed position shown in FIGA.

It is observable in the'various figures that the jaws are pivotable with respect to a central longitudinal separating plane M-M containing the pivotal axis 3 of the jaws. In the various stages of operation, the jaw portions 2S and 29 are equidistant from this plane, and cam surfaces 37, 38 extend along intersecting planes which intersect with the plane M-M to define a notched contour facing into the article-gripping region between the jaw portions 28, 29 and toward the article-receiving end of the device. In order to develop the cam action at surfaces 37 and 38 needed to rotate the jaws 10 and 14- to the closed position of FIG. 1, the cam surface 37, 33 of each jaw extends toward the other jaw from the end of the concave surface 28a, 29a of that jaw further away from the articlereceiving end of the device. In order to develop the desired camming action, each cam surface necessarily extends, at all positions of the jaws, at an angle inclined with respect to the plane of separation M-M toward the article-receiving end of the device. The cam surface 37, 38 of each jaw 10, 14 also faces toward the end of the concave surface of that jaw nearer the article-receiving end of the device. In order to form the notched contour, the surfaces 37 and 38 are of suflicient length to extend substantially beyond the plane M-M from respective parent jaw portions at all relative positions of the jaws.

FIGS. 5 and 6 show an environment in which a plurality of the device 5 is used. A spreader 45, centrally supported from a crane (not shown), comprises a device 5 at each of its four corners adapted to couple with bridge elements or rungs 35 fixed within the top structure of a container 48. The pin 13 of each device extends through adjacent structure of the spreader to provide pivotal attachment of the device thereto. The spreader i6 comprises a lever system comprising a central control lever and shaft assembly 51 and connecting rods 52 which extend from the assembly 51 into pinned connection with the portion 53 of the bell-crank 2l of each device 5. This lever system is used to retract the wedges 6 of all four devices simultaneously.

The terms and expressions which have been employed are used as terms of description and not of limitation, and there is no intention of excluding such equivalents of the invention described or of the portions thereof as fall within the scope of the claims.

What is claimed is:

l. A lifting device adapted to automatically couple with a load comprising: a pair of jaws extending longitudinally toward a load-receiving end of the device; means connecting the jaws in movable guide relation with each other disposing portions of both jaws in opposed relationship for movements toward and away from each other and from a plane of separation centered with respect to the jaws at all positions thereof; housing means in fixed relation with one jaw extending in a direction away from said plane to encompass the other jaw and beyond the latter jaw to encompass a range of movement thereof relative to said one jaw; wedge means, disposing between, and reacting with, said housing means and said other jaw through movement lengthwise of said other jaw to lock said jaws in progressively closer positions of said jaw portions; said jaw portions having substantially opposed concave surfaces facing into a central load-receiving region; each jaw having a cam surface extending, at all relative positions of the jaws, from the end of itswcon'cave surface further away from said load-receiving end toward the other jaw in a direction inclined with respect to said plane of separation toward said load-receiving end; said cam surfaces extending from respective jaws along planes which intersect, and extending beyond such plane intersection, at all relative positions of the jaws.

2. A lifting device comprising: a first jaw having a pair of spaced walls; a second jaw having a single wall disposed between the walls of the first jaw; said jaws having end portions defining concave surfaces at opposite sides of, and facing into a central article-gripping region; means arranged along an axis extending transversely through said walls in spaced relation with said end portions enabling relative pivoting of said jaws through a desired range of separation and closing of said jaw portions; said jaw portions being separable with respect to a plane of separation containing said axis each jaw having a cam surface contiguous with the end of its concave surface nearer said axis and facing toward the other end of said concave surface; the cam surfaces of both jaws extending along intersecting planes to define, at all positions of the jaws in said range, a notched contour comprising portions of both surfaces facing away from said axis into said region; the first jaw comprising a bridge wall connecting portions of said two walls spaced in a direction away from said separating plane and beyond the second jaw which define a pocket laterally outwardly adjacent the second jaw; and a Wedge element supported within said pocket for movement lengthwise of the jaws to engage both jaws in wedging relationship at closed relation of said jaw portions.

3. The lifting device of claim 2 comprising a bell-crank pivotally mounted on the first jaw for rotation in the plane of the second jaw and said element; said element having an opening and the bell-crank having an arm projecting into said opening in driving relation with the element.

4. The lifting device of claim 2 in combination with support means therefor connected in pivotal relation with the device at `said axis.

5. The lifting device of claim 2 wherein: said pocket encloses a surface slidably engaged by said element comprising a section engaged by the element at closed rell tion of the jaws and a second section nearer to said axis in contiguous and recessed relation with the first section;

the recessed section having a length sufficient for substantially full face-toface contact with the element and terminating away from the rst section in a shoulder surface; said shoulder limiting movement of the element longitudinally of the second jaw.

`6. The lifting device of claim 5 comprising spring means operatively disposed between said jaws for urging References Cited in the le of this patent UNITED STATES PATENTS Burns Apr. 23, 1957 Daum Aug. 22, 1961 

1. A LIFTING DEVICE ADAPTED TO AUTOMATICALLY COUPLED WITH A LOAD COMPRISING: A PAIR OF JAWS EXTENDING LONGITUDINALLY TOWARD A LOAD-RECEIVING END OF THE DEVICE; MEANS CONNECTING THE JAWS IN MOVABLE GUIDE RELATION WITH EACH OTHER DISPOSING PORTIONS OF BOTH JAWS IN OPPOSED RELATIONSHIP FOR MOVEMENTS TOWARD AND AWAY FROM EACH OTHER SAID FROM A PLANE OF SEPARATION CENTERED WITH RESPECT TO THE JAWS AT ALL POSITIONS THEREOF; HOUSING MEANS IN FIXED RELATION WITH ONE JAW EXTENDING IN A DIRECTION AWAY FROM SAID PLANE TO ENCOMPASS THE OTHER JAW AND BEYOND THE LATTER JAW TO ENCOMPASS A RANGE OF MOVEMENT THEREOF RELATIVE TO SAID ONE JAW; WEDGE MEANS, DISPOSING BETWEEN, AND REACTING WITH, SAID HOUSING MEANS AND SAID OTHER JAW THROUGH MOVEMENT LENGTHWISE OF SAID OTHER JAW TO LOCK SAID JAWS IN PROGRESSIVELY CLOSER POSITIONS OF SAID JAW PORTIONS; SAID JAW PORTIONS HAVING SUBSTANTIALLY OPPOSED CONCAVE SURFACES FACING INTO A CENTRAL LOAD-RECEIVING REGION; EACH JAW HAVING A CAM SURFACE EXTENDING, AT ALL RELATIVE POSITIONS OF THE JAWS, FROM THE END OF ITS CONCAVE SURFACE FURTHER AWAY FROM SAID LOAD-RECEIVING END TOWARD THE OTHER JAW IN A DIRECTION INCLINED WITH RESPECT TO SAID PLANE OF SEPARATION TOWARD SAID LOAD-RECEIVING END; SAID CAM SURFACES EXTENDING FROM RESPECTIVE JAWS ALONG PLANES WHICH INTERSECT, AND EXTENDING BEYOND SUCH PLANE INTERSECTION, AT ALL RELATIVE POSITIONS OF THE JAWS. 